Looking rather like a performance-enhancing bionic body part, the Leatt C-Frame knee brace is a one-sided hinged brace that is intended to protect the kneecap from impact, prevent joint hyperextension, and reduce twisting injuries by providing stability to the knee. The Leatt knee brace is something that adventure, trail, dual-sport, supermoto, enduro, motocross, and supercross riders should wear, as knees are a highly vulnerable part of your body off-road.The Leatt C-Frame knee brace is a beautiful piece of equipment. The carbon fiber shin protector is gracefully molded and interfaces smoothly with the aluminum hinge structure. Ten Allen bolts hold the unit together, allowing for individual replacement of any part of the system, should it become damaged or worn. Wide, strong Velcro straps allow for a secure fit, and the foam between your leg and the brace is high-quality and channeled for cooling.Initial set up for this comprehensive defense system takes a bit of time. However, once you have chosen the proper thickness of padding for the outer thigh, set the optional flexion range, and figured out a comfortable routine for fastening the various adjustable Velcro straps, putting on the Leatt C-Frame just becomes part of the drill when dressing for the dirt.The C-Frame is a bulky looking brace out of the box, and I was concerned that it might not fit under my riding pants. I’ve found that women’s off-road pants are generally not cut wide enough at the knee for serious knee brace protection.Despite kneecap protection that protrudes farther out from the C-Frame’s profile, and the beefy-looking curved aluminum C-arm, the Leatt brace fit comfortably under my Fly Racing Kinetic Women’s Racewear pants. Additionally, the shin plates are low profile, so were not a space hog in my Alpinestars Stella Tech 3 boots.The included ankle-to-upper-thigh under sock is meant to be folded back over the brace at the shin and thigh, which not only helps keeps the C-Frame in position, but makes sliding riding pants on and off much easier. There is no catching your pants’ mesh lining on Velcro straps, which has always been a problem with previous braces I’ve worn. So, while it requires more effort to use the sock, it’s an essential part of the Leatt C-Frame system.With an innovative double pivot hinge at the knee, intended to simulate the knee’s natural movement, walking is comfortable and unrestricted. Once you’re on your bike and riding, it would be easy to forget you didn’t have the brace on if it weren’t for the confidence the C-Frame knee brace inspires.The one-sided hinge allowed my knees to keep almost direct contact with the bike, impinged only slightly by the upper thigh plate. Having worn both the CTi Custom and the Leatt C-Frame knee braces, one can adapt to either design fairly quickly and any preference is purely personal.The C-Frame limits your knee range to within five degrees of straight in stock configuration. Extra stops are included, and can limit knee range to less than 20 degrees of straight. A Leatt insider told me he likes the most restrictive -20 setup, so I went with that.At no time did I feel limited by the stop, either when standing on the bike, rolling through bumps, putting my leg out in a turn, or walking in the pits. Without any doubt, the extra safety provided by the -20 setting gave me an additional piece of mind that allowed me to ride harder.Comfort is excellent, and the braces disappear from your mind after just a few minutes of riding when you are first wearing them. After that, you consider the feel of the brace to be part of the riding experience and you will feel as underdressed without the C-Frame knee brace as you would riding without a helmet.Addressing the problem of knee braces transferring excessive forces to the thigh or lower leg bones under extreme duress, Leatt designed fracture points into the upper and lower plates. These parts are replaceable, as mentioned, and that is certainly preferable than breaking one’s leg.As a nice little practical bonus, a well-sized duffel bag is included with the Leatt C-Force knee brace that smartly carries both braces in your gearbag without chance of damage of or by the braces.While I am more than happy to report that I did not test Leatt’s safety claims–I am already coming off ACL replacement surgery–the company’s ten-year history of design and innovation with neck braces has built a reputation that establishes the company as a leader in rider safety. What I can report is that the $599 Leatt C-Force knee braces (they are sold in pairs) are well built, comfortable, compatible with riding gear, and most importantly, allow me to ride with the self-assurance that comes from wearing top of the line equipment.